1. Field of the Invention
The invention relates to the field of lighting and light signaling, especially for automotive vehicles.
2. Description of the Related Art
In the field of lighting and light signaling for automotive vehicles, it is becoming increasingly common to use light sources based on light-emitting semiconductor components, for example, light-emitting diodes (LEDs). An LED component emits light rays when a voltage with a value that is at least equal to a threshold value, referred to as direct voltage, is applied to its terminals.
In a known manner, one or more LEDs of a lighting module for an automotive vehicle are supplied with power via means for controlling the power supply, which comprise converter circuits. The means for controlling the power supply are configured to convert an electric current of a first magnitude, for example delivered by a current source of the automotive vehicle, such as a battery, to a load current having a second magnitude which is different from the first.
The light emitted by an LED may, in a known manner, be coupled into a light guide having an entry face, through which the light rays emitted by the LED enter the guide, and an entry face, physically located a distance away from the entry face, through which the light rays leave the light guide. Between the entry face and the exit face, the light rays are guided within the light guide, typically using reflective elements positioned inside the light guide.
Different LEDs, capable, for example, of emitting light of different color or intensity, may be used in order to carry out different lighting functions of an automotive vehicle within one and the same lighting device. These may be, for example, the functions of high beam or turn indicator lights. These LEDs implementing different lighting functions may nonetheless be supplied with power and controlled by shared power supply and control circuits, thus decreasing the need to provide dedicated electronic circuits. However, coupling the light produced for various lighting functions into various light guides remains a space constraint in the design of lighting devices for an automotive vehicle.
It should be noted that various types of LEDs housed on one and the same printed circuit board generate different amounts of heat when they are in operation, and the heat generated may also depend on the lighting function carried out by the LEDs. Specifically, a turn indicator light or blinker emits light only intermittently. The same applies for the generation of heat associated therewith. However, an LED producing a high-luminosity daytime running light generates a more substantial amount of heat. In general, heat dissipation elements are used in order to avoid overheating the LEDs. In order to guarantee efficient thermal dissipation, these elements are, in a known manner, often oversized according to the LEDs of the lighting device which generate the most heat. This leads to an additional loss of efficiency and wasted space.